Problem: Solve for $f$ : $f\div -\dfrac{2}{3}= -\dfrac{1}{3}$ $f =\,$
Answer: Multiply both sides by $-\dfrac{2}{3}$ : $f\div -\dfrac{2}{3}{\cdot -\dfrac{2}{3}}= -\dfrac{1}{3}{\cdot -\dfrac{2}{3}}$ To simplify, remember that when the signs are the same, the product is positive. When the signs are different, the product is negative. $f\div \cancel{-\dfrac{2}{3}}\cdot \cancel{-\dfrac{2}{3}}-= \dfrac{2}{9}$ $f = \dfrac{2}{9}$